The present invention relates to the field of rolling bearings and of thrust bearing assemblies used, in particular, in motor vehicles with telescopic suspensions of steering wheels.
A thrust bearing assembly usually includes an upper ring and a lower ring between which are mounted rolling elements, for example balls or rollers.
A thrust bearing assembly is usually placed at the top of the suspension assembly, between a lower metal cup that also acts as a seat for a suspension spring, and an upper element secured to the vehicle body. The spring of the suspension device is installed around the rod of the damper piston whose end is secured to an elastic support block. The thrust bearing assembly allows a rotating motion between the spring cup, able to rotate, and the elastic support block that is attached to the vehicle body. The relative angular movement between the spring cup and the elastic block is the result of a turning of the steering wheel and/or the compression of the suspension spring.
The thrust bearing also transmits axial forces between the spring and the vehicle body.
EP 1 000 781 discloses a thrust bearing in which the rolling bearing comprises two rings and seals for sealing the gap between the rings.
U.S. Pat. No. 6,186,507 discloses a rotary shaft with sealing means comprising axial and radial contacting lips.
WO 07/037308 discloses a rolling bearing in which the sealing means comprise contacting lips and waterproof grease.
However, the bearing seals thus obtained are not satisfactory. Specifically, the contacting lips create a friction between the two parts of the rolling bearing. On the other hand, the rolling bearings are situated under the vehicle body and in the near vicinity of the wheels which, particularly during rainy weather, splash pollutants likely to enter the bearing, and pollution of the bearing by external elements may, in the long run, adversely affect the operation of the bearing.